Conventionally, signal couplers are used in demountable electronic devices such as smart cards. Smart cards are credit card size devices containing an integrated circuit, and in use are arranged to communicate to a base device through a signal coupler which provides an electrical connection for the flow of supply current and/or data signals between the base device and the integrated circuit of the smart card.
A problem with this arrangement is that in normal use, the contacts may become worn, thereby not efficiently transmitting the power supply or the data signals between the base device and the demountable device. Functionality of the circuit within the device may thereby be impaired or lost.
It is known to use an inductive connection composed of two inductive coils which do not require physical contact. However, very close proximity between the two coils is necessary for good functionality with this arrangement.
Furthermore, the coil of the device cannot easily be integrated with the circuit thereof, thereby placing a constraint on the minimum size of the device and convenience of manufacture.
This invention seeks to provide a signal coupler in which the above mentioned disadvantages have been mitigated.